Securitizations and Variable Interest Entities (Schedule of Cash Flow Received from and Paid to Nonconsolidated Securitization Entities) (Details) - Off-balance sheet variable interest entities - Consumer Automotive Industry Sector - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash flows received on retained interests in securitization entities	$ 4	$ 7
Cash flows between transferor and transferee, servicing fees	$ 1	3
Cash flows between transferor and transferee, disbursement for repurchases during the period		$ (1)